Basis of Presentation (Policies)	6 Months Ended
Basis of Presentation (Policies)	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting, Policy [Policy Text Block]	The accompanying unaudited consolidated financial statements have been prepared by West Bancorporation, Inc. (the Company) pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). Certain information and footnote disclosures normally included in financial statements have been condensed or omitted pursuant to such rules and regulations. Although management believes that the disclosures are adequate to make the information presented understandable, it is suggested that these interim consolidated financial statements be read in conjunction with the Company's Annual Report on Form 10-K for the year ended December 31, 2018 filed with the SEC on February 28, 2019. In the opinion of management, the accompanying consolidated financial statements of the Company contain all adjustments necessary to fairly present its financial position as of June 30, 2019 and December 31, 2018, net income, comprehensive income and changes in stockholders' equity for the three and six months ended June 30, 2019 and 2018, and cash flows for the six months ended June 30, 2019 and 2018. The results for these interim periods may not be indicative of results for the entire year or for any other period. The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (GAAP) established by the Financial Accounting Standards Board (FASB). References to GAAP issued by the FASB in these footnotes are to the FASB Accounting Standards Codification™, sometimes referred to as the Codification or ASC.
Use of Estimates, Policy [Policy Text Block]	In preparing the consolidated financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses for the reporting period. Actual results could differ from those estimates. Material estimates that are particularly susceptible to significant change in the near term are the fair value of financial instruments and the allowance for loan losses
Consolidation, Policy [Policy Text Block]	The accompanying unaudited consolidated financial statements include the accounts of the Company, West Bank, West Bank's special purpose subsidiaries and West Bank's wholly-owned subsidiary WB Funding Corporation (which was liquidated in March 2018). All significant intercompany transactions and balances have been eliminated in consolidation. In accordance with GAAP, West Bancorporation Capital Trust I is recorded on the books of the Company using the equity method of accounting and is not consolidated.
New Accounting Pronouncements, Policy [Policy Text Block]	Current accounting developments: In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842). The guidance in the update supersedes the requirements in ASC Topic 840, Leases. The guidance is intended to increase transparency and comparability among organizations by recognizing right-of-use assets and lease liabilities on the balance sheet. For public companies, this update was effective for interim and annual periods beginning after December 15, 2018. The Company adopted this guidance in the first quarter of 2019. Upon adoption, the Company elected a practical expedient which allowed existing leases to retain their classification as operating leases. The Company also elected the option to account for lease and related non-lease components as a single lease component, and the option not to recognize right-of-use assets and lease liabilities arising from short-term leases (leases with terms of twelve months or less). Lease liabilities are measured at the present value of the remaining lease payments, discounted at the Company's incremental borrowing rate. The right-of-use asset is measured at the amount of the lease liability adjusted for any cumulative prepaid or accrued rent if the lease payments are uneven throughout the lease term. Implementation of the guidance resulted in the recording of a right-of-use asset, included in premises and equipment, and an operating lease liability, included in other liabilities, on the consolidated balance sheet; however it did not have a material impact on the Company's other consolidated financial statements. See additional disclosures in Note 9. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326). The amendments in this update require a financial asset (or a group of financial assets) measured at amortized cost basis to be presented at the net amount expected to be collected. The allowance for credit losses is a valuation account that is deducted from the amortized cost basis of the financial assets to present the net carrying value at the amount expected to be collected on the financial assets. Under the updates, the income statement will reflect the measurement of credit losses for newly recognized financial assets, as well as the expected increases or decreases of expected credit losses that have taken place during the period. The measurement of expected credit losses is based on relevant information about past events, including historical experience, current conditions, and reasonable and supportable forecasts that affect the collectibility of the reported amount of financial assets. An entity must use judgment in determining the relevant information and estimation methods that are appropriate in its circumstances. The allowance for credit losses for purchased financial assets with a more-than-insignificant amount of credit deterioration since origination that are measured at amortized cost basis will be determined in a similar manner to other financial assets measured at amortized cost basis; however, the initial allowance for credit losses will be added to the purchase price rather than being reported as a credit loss expense. Only subsequent changes in the allowance for credit losses will be recorded as a credit loss expense for these assets. Off-balance-sheet arrangements such as commitments to extend credit, guarantees and standby letters of credit that are not considered derivatives under ASC 815 and are not unconditionally cancellable are also within the scope of this update. Credit losses relating to available for sale debt securities should be recorded through an allowance for credit losses. For public companies, the update is effective for annual periods beginning after December 15, 2019, including interim periods within those fiscal years. An entity will apply the amendments in this update on a modified retrospective basis through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is effective. In July 2019, the FASB proposed changes to the effective date of ASU No. 2016-13 for smaller reporting companies, as defined by the SEC, and other non-SEC reporting entities. The proposal would delay the effective date to fiscal years beginning after December 31, 2022, including interim periods within those fiscal periods. As the Company is a smaller reporting company, the proposed delay would be applicable to the Company, if it is approved by the FASB. The Company is developing its approach for determining the expected credit losses under the new guidance. The Company continues collecting and retaining historical loan and credit data and is currently evaluating alternative loss estimation models. While the Company currently cannot reasonably estimate the impact of adopting this standard, the Company expects the impact will be influenced by the composition, risk characteristics and quality of our loan and securities portfolios, as well as the general economic conditions and forecasts as of the adoption date. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this update modify the disclosure requirements for fair value measurements by removing, modifying, or adding certain disclosures. The update is effective for interim and annual periods in fiscal years beginning after December 15, 2019, with early adoption permitted for the removed disclosures and delayed adoption until fiscal year 2020 permitted for the new disclosures. The removed and modified disclosures will be adopted on a retrospective basis, and the new disclosures will be adopted on a prospective basis. The adoption will not have a material effect on the Company’s consolidated financial statements. In April 2019, the FASB issued ASU No. 2019-04, Codification Improvements to Financial Instruments - Credit Losses (ASC 326), Derivatives and Hedging (ASC 815), and Financial Instruments (ASC 825). The amendments in the ASU improve the Codification by eliminating inconsistencies and providing clarifications. The amended guidance in this ASU related to the credit losses will be effective for fiscal years and interim periods beginning after December 15, 2019. The Company is currently evaluating the impact of the ASU on the Company's consolidated financial statements.
Earnings Per Share, Policy [Policy Text Block]	Basic earnings per common share are computed by dividing net income by the weighted average number of common shares outstanding for the period. Diluted earnings per common share reflect the potential dilution that could occur if the Company's outstanding restricted stock units were vested. The dilutive effect was computed using the treasury stock method, which assumes all stock-based awards were exercised and the hypothetical proceeds from exercise were used by the Company to purchase common stock at the average market price during the period. The incremental shares, to the extent they would have been dilutive, were included in the denominator of the diluted earnings per common share calculation.
Loans and Leases Receivable, Origination Fees, Discounts or Premiums, and Direct Costs to Acquire Loans Policy [Policy Text Block]	Loans are stated at the principal amounts outstanding, net of unamortized loan fees and costs, with interest income recognized on the interest method based upon the terms of the loan. Loan origination fees, net of certain direct origination costs, are deferred and recognized as an adjustment of the related loan yield using the interest method. Loans are reported by the portfolio segments identified above and are analyzed by management on this basis.
Loans and Leases Receivable, Nonaccrual Loan and Lease Status, Policy [Policy Text Block]	Delinquencies are determined based on the payment terms of the individual loan agreements. The accrual of interest on past due and other impaired loans is generally discontinued at 90 days past due or when, in the opinion of management, the borrower may be unable to make all payments pursuant to contractual terms. Unless considered collectible, all interest accrued but not collected for loans that are placed on nonaccrual or charged off is reversed against interest income, if accrued in the current year, or charged to the allowance for loan losses, if accrued in the prior year. Generally, all payments received while a loan is on nonaccrual status are applied to the principal balance of the loan. Loans are returned to accrual status when all principal and interest amounts contractually due are brought current and future payments are reasonably assured.
Loans and Leases Receivable, Troubled Debt Restructuring Policy [Policy Text Block]	A loan is classified as a troubled debt restructured (TDR) loan when the Company separately concludes that a borrower is experiencing financial difficulties and a concession is granted that would not otherwise be considered. Concessions may include a restructuring of the loan terms to alleviate the burden of the borrower's cash requirements, such as an extension of the payment terms beyond the original maturity date or a change in the interest rate charged. TDR loans with extended payment terms are accounted for as impaired until performance is established. A change to the interest rate would change the classification of a loan to a TDR loan if the restructured loan yields a rate that is below a market rate for that of a new loan with comparable risk. TDR loans with below-market rates are considered impaired until fully collected. TDR loans may also be reported as nonaccrual or 90 days past due if they are not performing per the restructured terms.
Impaired Financing Receivable, Policy [Policy Text Block]	Based upon its ongoing assessment of credit quality within the loan portfolio, the Company maintains a Watch List, which includes loans classified as Doubtful, Substandard and Watch according to the Company's classification criteria. These loans involve the anticipated potential for payment defaults or collateral inadequacies. A loan on the Watch List is considered impaired when management believes it is probable the Company will be unable to collect all contractual principal and interest payments due in accordance with the terms of the loan agreement. Impaired loans are measured based on the present value of expected future cash flows discounted at the loan's effective interest rate or, as a practical expedient, at the loan's observable market price or the fair value of the collateral if the loan is collateral dependent. The amount of impairment, if any, and any subsequent changes are included in the allowance for loan losses.
Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block]	The allowance for loan losses is established through a provision for loan losses charged to expense. The allowance is an amount that management believes will be adequate to absorb probable losses on existing loans based on an evaluation of the collectability of loans and prior loss experience. This evaluation also takes into consideration such factors as changes in the nature and volume of the loan portfolio, overall portfolio quality, the review of specific problem loans, and the current economic conditions that may affect the borrower's ability to pay. Loans are charged-off against the allowance for loan losses when management believes that collectability of the principal is unlikely. While management uses the best information available to make its evaluations, future adjustments to the allowance may be necessary if there are significant changes in economic conditions or the other factors relied upon. The allowance for loan losses consists of specific and general components. The specific component relates to loans that meet the definition of impaired. The general component covers the remaining loans and is based on historical loss experience adjusted for qualitative factors such as delinquency trends, loan growth, economic elements and local market conditions. These same policies are applied to all segments of loans. In addition, regulatory agencies, as an integral part of their examination processes, periodically review the Company's allowance for loan losses, and may require the Company to make additions to the allowance based on their judgment about information available to them at the time of their examinations.
Fair Value Measurement, Policy [Policy Text Block]	Accounting guidance on fair value measurements and disclosures defines fair value and establishes a framework for measuring the fair value of assets and liabilities using a hierarchy system. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants in the market in which the reporting entity transacts business. The Company's balance sheet contains investment securities available for sale and derivative instruments that are recorded at fair value on a recurring basis. The three-level valuation hierarchy for disclosure of fair value is as follows: Level 1 uses quoted market prices in active markets for identical assets or liabilities. Level 2 uses observable market-based inputs or unobservable inputs that are corroborated by market data. Level 3 uses unobservable inputs that are not corroborated by market data. The Company's policy is to recognize transfers between levels at the end of each reporting period, if applicable. There were no transfers between levels of the fair value hierarchy during the six months ended June 30, 2019. The following is a description of valuation methodologies used for financial assets and liabilities recorded at fair value on a recurring basis. Investment securities available for sale: When available, quoted market prices are used to determine the fair value of investment securities (Level 1). If quoted market prices are not available, the Company determines fair value based on various sources and may apply matrix pricing with observable prices for similar bonds where a price for the identical bond is not observable (Level 2). The fair values of these securities are determined by pricing models that consider observable market data such as interest rate volatilities, LIBOR yield curve, credit spreads, prices from market makers and live trading systems. For the corporate bond portfolio, the Company has elected to use a matrix pricing model as a practical expedient to individual quoted market prices. Generally, management obtains the fair value of investment securities at the end of each reporting period via a third-party pricing service. Management reviewed the valuation process used by the third party and believed the process was valid. On a quarterly basis, management corroborates the fair values of a randomly selected sample of investment securities by obtaining pricing from an independent financial market data vendor and comparing the two sets of fair values. Any significant variances are reviewed and investigated. For a sample of securities, prices are further validated by management by obtaining details of the inputs used by the pricing service. Those inputs were independently tested, and management concluded the fair values were consistent with GAAP requirements and the investment securities were properly classified in the fair value hierarchy. Derivative instruments: The Company's derivative instruments consist of interest rate swaps, which are accounted for as cash flow hedges. The Company's derivative positions are classified within Level 2 of the fair value hierarchy and are valued using models generally accepted in the financial services industry and that use actively quoted or observable market input values from external market data providers and/or non-binding broker-dealer quotations. The fair value of the derivatives is determined using discounted cash flow models. These models’ key assumptions include the contractual terms of the respective contract along with significant observable inputs, including interest rates, yield curves, nonperformance risk and volatility.
Fair Value Transfer, Policy [Policy Text Block]	The Company's policy is to recognize transfers between levels at the end of each reporting period, if applicable.
Fair Value of Financial Instruments, Policy [Policy Text Block]	GAAP requires disclosure of the fair value of financial assets and financial liabilities, including those that are not measured and reported at fair value on a recurring or nonrecurring basis.
Off-Balance-Sheet Credit Exposure, Policy [Policy Text Block]	The Company is party to financial instruments with off-balance-sheet risk in the normal course of business to meet the financing needs of its customers. These financial instruments include commitments to extend credit and standby letters of credit. These instruments involve, to varying degrees, elements of credit risk in excess of the amount recognized in the consolidated balance sheets. The Company's exposure to credit loss in the event of nonperformance by the other party to the financial instrument for commitments to extend credit and standby letters of credit is represented by the contractual amount of those instruments. The Company uses the same credit policies in making commitments and conditional obligations that it uses for on-balance-sheet instruments.